templates: add filter to reverse list
The filter supports only lists because for lists, it’s straightforward to
implement. Reversing text doesn’t seem very useful and is hard to implement.
Reversing the bytes would break multi-bytes encodings. Reversing the code
points would break characters consisting of multiple code points. Reversing
graphemes is non-trivial without using a library not included in the standard
library.
#!/usr/bin/env python3
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump
import sys
from mercurial.node import bin
from mercurial import (
encoding,
revlog,
transaction,
vfs as vfsmod,
)
from mercurial.utils import procutil
from mercurial.revlogutils import (
constants as revlog_constants,
)
for fp in (sys.stdin, sys.stdout, sys.stderr):
procutil.setbinary(fp)
opener = vfsmod.vfs(b'.', False)
tr = transaction.transaction(
sys.stderr.write, opener, {b'store': opener}, b"undump.journal"
)
while True:
l = sys.stdin.readline()
if not l:
break
if l.startswith("file:"):
f = encoding.strtolocal(l[6:-1])
assert f.endswith(b'.i')
r = revlog.revlog(
opener,
target=(revlog_constants.KIND_OTHER, b'undump-revlog'),
radix=f[:-2],
)
procutil.stdout.write(b'%s\n' % f)
elif l.startswith("node:"):
n = bin(l[6:-1])
elif l.startswith("linkrev:"):
lr = int(l[9:-1])
elif l.startswith("parents:"):
p = l[9:-1].split()
p1 = bin(p[0])
p2 = bin(p[1])
elif l.startswith("length:"):
length = int(l[8:-1])
sys.stdin.readline() # start marker
d = encoding.strtolocal(sys.stdin.read(length))
sys.stdin.readline() # end marker
r.addrevision(d, tr, lr, p1, p2)
tr.close()